Question

My question is about a case where things work fine for a method with one parameter, but not for two. The code comes from Apple animation sample code.

the main view object, (self), has readonly reference to an abstract superclass object, s.

It can call methods on an instance that inherits from the superclass like this:

[self.s myMethod:param1];

and it works fine.

However, when I try:

[self.s anotherMethod:param1 secondParam:param2];

I get the compile error:

Semantic Issue > Instance method ‘-anotherMethod:secondParam:’ not found (return type
defaults to ‘id’)

Both the methods have return type – (void).

Everything is declared and defined in the same way for the first case and the second.

Any suggestions would be greatly appreciated.

(I don’t really want to resort to bundling up parameters into a single object!)

---

amendment with example added below

declarations like this in .h files of superclass and inherited class

for the super class:

@interface SuperClass : NSObject
{
...
}
...
- (void) myMethod:(SomeObject *) param1;
- (void) anotherMethod:(SomeObject *) param1: (int) param2;
@end

for the inherited class:

#import "SuperClass.h"
@interface InheritedClass : SuperClass
{
...
}
...
- (void) myMethod:(SomeObject *) param1;
- (void) anotherMethod:(SomeObject *) param1: (int) param2;
@end

implementations in .m file of each class

have tried adding this to the inherited class .m file.

@interface InheritedClass ()
- (void) anotherMethod:(SomeObject *) param1: (int) param2;
@end

Answer 1

This call:

[self.s anotherMethod:param1 secondParam:param2];

…means the method name is anotherMethod:secondParam:.

This declaration:

- (void) anotherMethod:(SomeObject *) param1: (int) param2;

…does not have the same name.

Is it possible that you meant to say:

- (void) anotherMethod:(SomeObject *)param1 secondParam:(int)param2;

?